1. Field of the Invention
The invention relates to a stereo/two-tone demodulator for demodulating an intermediate-frequency signal comprising stereo or two-tone sound signals modulated on a first and a second sound carrier, the second sound carrier having a lower amplitude than the first sound carrier.
2. Description of the Related Art
When a stereo or a two-tone signal is transmitted, an intermediate-frequency signal, which may also comprise a picture signal, has two sound carriers on which ,sound signal components are modulated. Dependent on the transmission standard, the two sound carriers do not have equal amplitudes. One of the sound carriers may be up to 20 dB smaller as compared with the other.
In known stereo/two-tone demodulators, either ceramic bandpass filters preceding the demodulator are used, or bandpass filters are arranged within the demodulator. Since such demodulators are usually built into integrated circuits, such bandpass filters interfere because they cannot be realized within the IC but must be realized by means of additional external components which do not only require an additional external number of components, but the IC must also be provided, with equally additional connection, which is also detrimental.